Probability of Reaction Pathways of Amine With Epoxides in the Reagent Ratio of 1:1 and 1:2

The algorithm for generating and estimating the probability of possible reaction pathways for multichannel bimolecular interactions was used to predict the reaction products in the reagent ratio of 1:1 and 1:2. Here we have considered the possible reaction pathways of the reaction of amine ((1S,2S,4S)-bicyclo[2.2.1]hept-5-en-2-ylmethanamine (1) with epoxides (2-((cyclohexyloxy)methyl)oxirane (2), 2-(phenoxymethyl)oxirane (3), (N-(oxiran-2-ylmethyl)-N-phenylbenzenesulfonamide 8) in order to explain experimental observed data, which indicate differences in the reactivity of glycidyl ethers and glycidylsulfonamide with framework amines. Based on the proposed algorithm [39], we have investigated the reaction in the reagent ratio of 1:1 and 1: 2. Calculated values of activation barriers indicate a low probability of formation of interaction products of amine (1) with epoxide (8) with a (1:2) reagent ratio due to steric hindrances in the reaction center.

New Star-Shaped Polyether-Pentols (PEPOs) for Fabrication of Crosslinked Polyurethanes—Synthesis and Characterization

Polyether-pentols (PEPOs) were synthesized from glycidyl ethers and butylene oxide with the application of tripotassium salts of 2,2,6,6-tetrakis(hydroxymethyl)cyclohexanol (HMCH) activated 18C6 for ring-opening polymerization (ROP). The construction of the applied initiator system reflects the ability of crown ether to influence the degree of ion-pair separation with an increased activating effect. As a result formation of bi- or trimodal polymers was observed with molar masses in the range of (Mn = 1200–6000). The observed multi-fraction composition is prescribed to the formation of ionic aggregates with different reactivities during polymerization. The mechanism of the studied processes is discussed. The obtained PEPOs served for a crosslinked PUR synthesis, for which the hydrogen bond index for coupling of hard segments was calculated. Additionally, the range of phase separation was calculated that was higher for PUR-containing aromatic rings as the substituent.

Application of Monopotassium Dipropylene Glycoxide for Homopolymerization and Copolymerization of Monosubstituted Oxiranes: Characterization of Synthesized Macrodiols by MALDI-TOF Mass Spectrometry

Monopotassium dipropylene glycoxide, activated by a 18-crown-6 cation complexing agent (K-DPG/L, where DPG (dipropylene glycol) is a mixture of isomers) was used as an effective initiator of the homopolymerization and copolymerization of several monosubstituted oxiranes, i.e., propylene oxide (PO), 1.2-butylene oxide (BO), and some glycidyl ethers such as allyl, isopropyl, phenyl, and benzyl ones (AGE, IPGE, PGE, and BGE, respectively). The copolymers are novel and can be prospectively used for the fabrication of new thermoplastic or crosslinked polyurethanes. All processes were carried out in homogeneous mild conditions, i.e., tetrahydrofuran solution at room temperature and normal pressure. They resulted in new unimodal macrodiols with Mn = Mcalc in the range of 1500–8300, low dispersity Mw/Mn = 1.08–1.18 and a chemical structure well defined by several techniques, i.e., MALDI-TOF, size exclusion chromatography (SEC), 13C NMR, and FTIR. Monopotassium salts of homopolyether-diols, i.e., PPO-diol, PBO-diol, and PAGE-diol, appeared to be useful macroinitiators for the preparation of new triblock copolyether-diols by polymerization of glycidyl ethers. In BO/BGE random copolymerization initiated with K-DPG/L, macromolecules of copolyether-diol were exclusively formed. Macromolecules of copolyether-diol accompanied by homopolyether PPO-diol were identified in the PO/PGE system. However, AGE and PGE reacted by giving random copolyether-diol as well as homopolymer-diols, i.e., PAGE-diol and PPGE-diol. Macromolecules of prepared copolyether-diols contain various numbers of mers deriving from comonomers; the kind of comonomer determines the composition of the product. Several prepared homopolyether-diols and copolyether-diols could be useful for the synthesis of new thermoplastic polyurethanes.

Application of cesium hydroxide monohydrate for ring opening polymerization of monosubstituted oxiranes: characterization of synthesized polyether-diols

Cesium hydroxide monohydrate (CsOH·H2O) activated by cation complexing agents, i.e., 18C6 or C222 was applied as initiator of monosubstituted oxiranes polymerization. Propylene oxide (PO), 1,2-butylene oxide (BO), styrene oxide (SO) and some glycidyl ethers were used as monomers. All processes were carried out in tetrahydrofuran solution at room temperature. Such polymers, as PPO-diols, PBO-diols and PSO-diols, are unimodal and have molar masses Mn = 2000–5100. Their dispersities are rather high (Mw/Mn = 1.17–1.33). Moreover, PPO-diols and PSO-diols are not contaminated by monools with unsaturated starting groups. Poly(glycidyl ether)s are, in general, polymodal. For example, poly(isopropyl glycidyl ether)-diols are bi- or trimodal, whereas poly(allyl glycidyl ether)-diols possess two or even six fractions. Molar masses of main fraction are 4200–6400, and the second fraction is much lower, namely 600–2600. Dispersities of some fractions are very low (Mw/Mn = 1.01–1.07). Polymodality of polymers obtained was discussed in terms of the formation of two or more species propagating with different rate constants. Graphic abstract

Oxidation Level and Glycidyl Ether Structure Determine Thermal Processability and Thermomechanical Properties of Arabinoxylan-Derived Thermoplastics

Herein we present arabinoxylan (AX)-based thermoplastics obtained by ring opening oxidation and subsequent reduction (dA-AX) combined with hydrophobization with three different glycidyl ethers [n-butyl (BuGE), isopropyl (iPrGE) and 2-ethylhexyl (EtHGE) glycidyl ether]. We also present the relationship of structural composition, thermal processing and thermomechanical properties. The BuGE and iPrGE etherified dA-AXs showed glass transition temperatures (T_g) far below their degradation temperatures and gave thermoplastic materials when compression-molded at 140˚C. The BuGE (3 mole) etherified dA-AX films at 19 and 31 % oxidation levels exclusively exhibit 244 % (±42) and 267 % (±72) elongation. In contrast, iPrGE-dA-AX samples with shorter and branched terminals in the side chains had maximum 60 % (±19) elongation. The dramatic difference in elongation is assumed to be due to the presence of longer alkoxide chains, higher molar substitution and dual T_g for the BuGE samples. Such superior elongation of AX thermoplastic films and its relationship with molar substitution and T_g has not been reported before.

Oxidation Level and Glycidyl Ether Structure Determine Thermal Processability and Thermomechanical Properties of Arabinoxylan-Derived Thermoplastics

Herein we present arabinoxylan (AX)-based thermoplastics obtained by ring opening oxidation and subsequent reduction (dA-AX) combined with hydrophobization with three different glycidyl ethers [n-butyl (BuGE), isopropyl (iPrGE) and 2-ethylhexyl (EtHGE) glycidyl ether]. We also present the relationship of structural composition, thermal processing and thermomechanical properties. The BuGE and iPrGE etherified dA-AXs showed glass transition temperatures (T_g) far below their degradation temperatures and gave thermoplastic materials when compression-molded at 140˚C. The BuGE (3 mole) etherified dA-AX films at 19 and 31 % oxidation levels exclusively exhibit 244 % (±42) and 267 % (±72) elongation. In contrast, iPrGE-dA-AX samples with shorter and branched terminals in the side chains had maximum 60 % (±19) elongation. The dramatic difference in elongation is assumed to be due to the presence of longer alkoxide chains, higher molar substitution and dual T_g for the BuGE samples. Such superior elongation of AX thermoplastic films and its relationship with molar substitution and T_g has not been reported before.

EPOXY POLYMERS BASED ON DIGLYCIDYL ETHERS WITH CYCLIC GROUPS

Glycidyl ethers of polycyclic bisphenols of norbornan type and their phenyl substituted derivatives were obtained and studied. They were solidified by diaminodiphenylsulphon and methyltetrahydrophthalic anhydride. The data of the termogravimetric analysis of the obtained polymers showed that they are characterizes by high thermal – and heat stability.The properties of polymers depend on the structure of the hardener and its chemical nature as well. The properties of polymers were sharply changed when glycidyl derivatives of bisphenols were cured by hardeners of different chemical structure. The presence of cyclic structures in the hardener molecule causes considerable increase of their thermal stability. Polymers on the basis of chlorine substituted glycidyl ethers of polycyclic bisphenols are characterized by incombustibility.

Investigation of surface tension and contact angles for effective polymer binders based on epoxy oligomers and active diluents

Objectives. This study focused on the quantification of the surface tension and the static and dynamic contact angles of epoxy oligomers, active diluents, and their mixtures of various compositions at different temperatures. The active diluents were aliphatic compounds based on glycidyl ethers, namely laproxides and a laprolate of different structure, functionality, molecular weight, and viscosity. Moreover, the preparation of effective polymer binders (matrices) for composites was explored.Methods. In this study, the epoxy oligomers ED-20 and DER-330, laproxides 201B, DEG-1, E-181, and 703, laprolate 301, and their mixtures in various compositions were investigated. Their surface tension and the static and dynamic contact angles were determined by the Wilhelmy plate and ring methods on a semiautomatic tensiometer at different temperatures (20–60 °C). The static contact angle was measured on a thin aluminum borosilicate glass plate, and the dynamic contact angles were determined using an installation for measuring surface tension developed by NPO Stekloplastik.Results. The surface tension and static and dynamic contact angles were obtained for all epoxy oligomers and active diluents, as well as for their mixtures at 20–60 °C. For binders based on systems of epoxy oligomers and active diluents, the impregnation rate of fiber reinforcement was also calculated. The introduction of laproxides or laprolates into the epoxy oligomers led to a decrease in surface tension and contact angles, while the increase in temperature increased the impregnation rate by 10–20 times.Conclusions. The temperature increase from 20 to 60 °C resulted in a decrease in the surface tension of mixed systems of epoxy oligomers and active diluents by almost two times. In addition, the contact angles changed by only 4°–7°, while the impregnation was significantly improved and the corresponding rate increased by 10–20 times.